This invention relates generally to manufacturing of Micro Electromechanical System (MEMS) devices, and more specifically to, getter devices and problems caused by gettering materials within MEMS devices.
Micro-electromechanical systems (MEMS) include electrical and mechanical components integrated on the same substrate, for example, a silicon substrate. Substrates for MEMS devices are sometimes referred to as dies. The electrical components are fabricated using integrated circuit processes, while the mechanical components are fabricated using micromachining processes that are compatible with the integrated circuit processes. This combination makes it possible to fabricate an entire system that fits within a chip carrier using standard manufacturing processes.
One common application of MEMS devices is utilization within inertial sensor. The mechanical portion of the MEMS device provides the sensing capability for the inertial sensor, while the electrical portion of the MEMS device processes the information received from the mechanical portion. One example of an inertial sensor that utilizes a MEMS device is a gyroscope.
The MEMS production process involves the placement of the operational portion of the MEMS device, sometimes referred to as a micro-machine, within a chip carrier or housing, which is then hermetically sealed. Getters are sometimes attached to the housing to facilitate removal of water vapor and hydrogen, for example.
Getters can however, release particles that can interfere with operation of the MEMs device. In one example, a MEMS gyroscope and other MEMS based inertial devices can be exposed to high-G forces that may cause an amount of particles to be released from the getter, and come into contact with moving components of the MEMS device.